The present invention relates to a heat exchanger for flowing fluids and, in particular, to a modular heat exchanger wherein each of the core modules is formed from a unitary block of heat exchange material.
Typically, conventional of heat exchangers for use in automobiles utilize heat exchanging core elements which include a series of generally parallel tubular conduits extending between and attached at their opposite ends to inlet and outlet headers. The tubular conduits are provided with heat conducting and dissipating fins which may be either of a flat plate or serpentine construction, and which are soldered or brazed to the tubular conduits. The conduits, in turn, are soldered or brazed to the headers or to similar fluid accumulating tanks.
The rigid soldered or brazed joints have always constituted a common source of heat exchanger failure and, when the heat exchangers are used in automotive applications, usually require removal of the entire radiator for repair, thereby resulting in down time for the automotive equipment. Thus, there has been a long need and desire for both a heat exchanger having unitary core elements and for one in which brazed or soldered connections can be minimized and, preferably, eliminated completely.
U.S. Pat. No. 5,303,770 discloses a modular heat exchanger which includes unitary finned tubular core elements which can be assembled into a multi-module heat exchanger, including flow distributing headers or end tanks without brazed, soldered, or welded connections of any kind. The heat exchanger is fully disassemblable in one embodiment, however, mechanical connectors and a substantial number of o-ring seals are required for assembly. In another embodiment, welded or brazed connections may be utilized to provide units which are partially disassemblable. However, these units are potentially subject to the prior art problems of inadequate joint strength and environmentally less desirable materials.
U.S. Pat. No. 5,383,517 discloses a modular heat exchanger having unitary finned tubular core elements which can be assembled into a multi-modular heat exchanger without any brazed, soldered or welded connections or mechanical connectors. The modules are formed from extruded aluminum blocks into which heat exchanging fins are cut or cold formed. Flow accumulating passages are bored into the ends of the modules. The modules are assembled with a high strength adhesive sealant which simultaneously secures the modules together and seals the peripheries of the bore passages at the module interfaces. However, it has been found during certain applications, increased heat dissipation by the heat exchanging fins is necessary.
Therefore, as a primary object and feature of the present invention to provide a modular heat exchanger which may be assembled without any brazed, soldered or welded connections or mechanical connectors.
It is a further object and feature of the present invention to provide a modular heat exchanger with increased heat dissipating ability.
It is a still further object and feature of the present invention to provide a modular heat exchanger wherein the modules may be formed from extruded aluminum blocks in to which the heat exchanging fins are cut or cold formed.
In accordance with the present invention, a modular heat exchanger is provided for a fluid flow. The modular heat exchanger a plurality of modules formed from heat transfer material. Each module has a generally rectangular cross section and a through bore extending longitudinally therethrough between parallel opposite faces. Each face includes a first set of equally spaced slots extending fully across the face in a direction transverse to the longitudinal axis of the through bore so as to define a series of parallel fins. Each face also includes a second set of equally spaced, parallel slots extending fully across the face in a direction parallel to the longitudinal axis of the bore. Each parallel fin includes a plurality of outer edges. A portion of the outer edges of the fins of a module abuts the outer edge of the fins on an adjacent module when the modules are placed together in face-to-face contact.
It is contemplated that each of the second set of equally spaced, parallel slots have a generally V-shaped cross section. This, in turn, causes each fin to include a set of equally spaced, generally triangular teeth extending across the face in a direction transverse to the longitudinal axis of the through bore. In order to increase the turbulence of the air flowing through the modular heat exchanger of the present invention, each tooth of each fin may be bent at a predetermined angle to the longitudinal axis of the through bore.
If the teeth are not bent, the first set of equally spaced slots has a generally rectangular cross section. The depth of the first set of equally spaced slots is greater than the depth of the second set of equally spaced, parallel slots having the generally V-shaped cross section.
It is further contemplated to provide a cross bore perpendicular to and passing through abutting faces of the modules and intersecting the through bores at each end of the module. The through bores are oblong in cross section and include a plurality of ribs extending along their inner surface.
In an alternate embodiment, a modular heat exchanger is provided for a fluid flow. The modular heat exchanger includes a plurality of modules formed from heat transfer material. Each module has a generally rectangular cross section and through bore extending longitudinally therethrough between parallel opposite faces.
A plurality of equally spaced fins extend across each face of a corresponding module in a direction transverse to the longitudinal axis of the through bore. Each fin includes a plurality of spaced teeth terminating at an outer edge. A portion of the outer edge of each tooth on a corresponding face of the module abuts the outer edge of a tooth on an adjacent module when the modules are placed together in face-to-face contact.
In accordance with the present invention, a module is provided for use in a modular heat exchanger. The module includes a generally rectangular element formed from a heat transfer material. The element has a generally rectangular cross section and a through bore extending longitudinally therethrough between parallel opposite faces. Each face includes a set of equally spaced parallel slots having a generally V-shaped cross section extending fully across the face in a direction parallel to the longitudinal axis of the through bore.
It is further contemplated to provide each face with a second set of equally spaced slots extending fully across the face in a direction transverse to the longitudinal axis of the through bore so as to define a series of parallel fins along each face.
As previously described, the through bores are oblong in cross section and defined by an inner surface of the module. A plurality of ribs extends along the inner surface of the module for the full length of the through bore.